Anthomyia Flies

(Family Anthomyiidae.)
The flies of this family also as a rule belong to the house fly type. They are generally rather small but of unpronounced color. It is a very large family and a most difficult one to study and the flies themselves are singularly unattractive in general appearance. Nevertheless, the habits of many of the species are of interest and they feed not only upon decaying vegetable matter but also upon growing plants and a few prey upon the eggs of grasshoppers. Such a wide variation in habit suggests that structural characters will eventually be found which will split up this large family.

Several species will be found mentioned in medical works under the head of "myiasis interna" and in these cases they have been taken into the stomachs of human beings with spoiled vegetables. They frequently retain their vitality and issue alive with the faeces. The insects commonly known as little house flies (Homalomyia canicularis and H. brevis) frequently seen in houses on windows belong to this family.

They breed in decaying vegetable material and dung. The so-called onion fly in the larval stage is occasionally very destructive to onions, working into the bulb and destroying it for food. The cabbage maggot (P. brassicae) works in the roots of cabbage and sometimes does great damage. Some species in the larval stage mine the leaves of plants. Pegomyia vicina mines the leaves of beets and has become a rather important insect since the cultivation of the sugar beet has assumed large proportions in this country.

One species is said to damage seed corn when placed in the ground and others destroy injurious grasshoppers and there are records which show that other forms sometimes live in tumors under the skin of birds.